Syrups are produced from starch, which is liquefied in the presence of acid or enzymes or both to convert the starch to smaller carbohydrate chains. The particular carbohydrate composition of the syrup is determined by the starting material as well as the acid and/or enzyme used, the temperature and pH at which the starch is liquefied, and the length of time the starch is exposed to the acid and/or enzyme. For example, the conversion of starch can be halted at an early stage resulting predominantly in polysaccharides, which generally produce low-to-medium sweetness syrups with medium-to-low humectancy, or the conversion can be allowed to proceed until the carbohydrates are nearly all dextrose, which generally produce sweet syrups with high hygroscopocity and humectancy.
Syrups are widely used in the manufacture of foods and beverages. In many cases, it is the individual saccharides or groups of saccharides (in other words, the carbohydrate composition) that determine syrup characteristics. Managing moisture is one of the most important functional properties that carbohydrate syrups contribute in various foods. In general, hygroscopicity (the property of adsorping moisture or picking up moisture) and humectancy (the property of retaining moisture or, conversely, not losing moisture) increase with the increase of mono- and di-saccharides or the increase of DE values of syrup products. High conversion starch syrups with more than 25% total mono- and di-saccharides and/or typically a dextrose equivalence (DE) of over 40 to 50 are used in various food products where humectancy is required, such as bakery products and soft chewy bars. Whereas low conversion starch syrups with less than 25% total mono- and di-saccharides and/or typically less than DE of 40 to 50 are used in applications where hygroscopicity needs to be avoided, such as hard candies and cereal coatings. These physiochemical properties are of particular importance to food manufacturing practices. Properties, such as appearance, texture, and mouthfeel of finished foods are also affected by the syrup used because of their physicochemical properties such as sweetness, hygroscopicity, and humectancy attributes.